<template>
  <view id="_root" :class="(selectable?'_select ':'')+'_root'" :style="containerStyle">
    <slot v-if="!nodes[0]" />
    <!-- #ifndef APP-PLUS-NVUE -->
    <node v-else :childs="nodes" :opts="[lazyLoad,loadingImg,errorImg,showImgMenu,selectable]" name="span" />
    <!-- #endif -->
    <!-- #ifdef APP-PLUS-NVUE -->
    <web-view ref="web" src="/static/app-plus/mp-html/local.html" :style="'margin-top:-2px;height:' + height + 'px'" @onPostMessage="_onMessage" />
    <!-- #endif -->
  </view>
</template>

<script>
  /**
   * mp-html v2.4.3
   * @description 富文本组件
   * @tutorial https://github.com/jin-yufeng/mp-html
   * @property {String} container-style 容器的样式
   * @property {String} content 用于渲染的 html 字符串
   * @property {Boolean} copy-link 是否允许外部链接被点击时自动复制
   * @property {String} domain 主域名，用于拼接链接
   * @property {String} error-img 图片出错时的占位图链接
   * @property {Boolean} lazy-load 是否开启图片懒加载
   * @property {string} loading-img 图片加载过程中的占位图链接
   * @property {Boolean} pause-video 是否在播放一个视频时自动暂停其他视频
   * @property {Boolean} preview-img 是否允许图片被点击时自动预览
   * @property {Boolean} scroll-table 是否给每个表格添加一个滚动层使其能单独横向滚动
   * @property {Boolean | String} selectable 是否开启长按复制
   * @property {Boolean} set-title 是否将 title 标签的内容设置到页面标题
   * @property {Boolean} show-img-menu 是否允许图片被长按时显示菜单
   * @property {Object} tag-style 标签的默认样式
   * @property {Boolean | Number} use-anchor 是否使用锚点链接
   * @event {Function} load dom 结构加载完毕时触发
   * @event {Function} ready 所有图片加载完毕时触发
   * @event {Function} imgtap 图片被点击时触发
   * @event {Function} linktap 链接被点击时触发
   * @event {Function} play 音视频播放时触发
   * @event {Function} error 媒体加载出错时触发
   */
  // #ifndef APP-PLUS-NVUE
  import node from './node/node'
  // #endif
  import Parser from './parser'
  const plugins = []
  // #ifdef APP-PLUS-NVUE
  const dom = weex.requireModule('dom')
  // #endif
  export default {
    name: 'mp-html',
    data () {
      return {
        nodes: [],
        // #ifdef APP-PLUS-NVUE
        height: 3
        // #endif
      }
    },
    props: {
      containerStyle: {
        type: String,
        default: ''
      },
      content: {
        type: String,
        default: ''
      },
      copyLink: {
        type: [Boolean, String],
        default: true
      },
      domain: String,
      errorImg: {
        type: String,
        default: ''
      },
      lazyLoad: {
        type: [Boolean, String],
        default: false
      },
      loadingImg: {
        type: String,
        default: ''
      },
      pauseVideo: {
        type: [Boolean, String],
        default: true
      },
      previewImg: {
        type: [Boolean, String],
        default: true
      },
      scrollTable: [Boolean, String],
      selectable: [Boolean, String],
      setTitle: {
        type: [Boolean, String],
        default: true
      },
      showImgMenu: {
        type: [Boolean, String],
        default: true
      },
      tagStyle: Object,
      useAnchor: [Boolean, Number]
    },
    // #ifdef VUE3
    emits: ['load', 'ready', 'imgtap', 'linktap', 'play', 'error'],
    // #endif
    // #ifndef APP-PLUS-NVUE
    components: {
      node
    },
    // #endif
    watch: {
      content (content) {
        this.setContent(content)
      }
    },
    created () {
      this.plugins = []
      for (let i = plugins.length; i--;) {
        this.plugins.push(new plugins[i](this))
      }
    },
    mounted () {
      if (this.content && !this.nodes.length) {
        this.setContent(this.content)
      }
    },
    beforeDestroy () {
      this._hook('onDetached')
    },
    methods: {
      /**
       * @description 将锚点跳转的范围限定在一个 scroll-view 内
       * @param {Object} page scroll-view 所在页面的示例
       * @param {String} selector scroll-view 的选择器
       * @param {String} scrollTop scroll-view scroll-top 属性绑定的变量名
       */
      in (page, selector, scrollTop) {
        // #ifndef APP-PLUS-NVUE
        if (page && selector && scrollTop) {
          this._in = {
            page,
            selector,
            scrollTop
          }
        }
        // #endif
      },

      /**
       * @description 锚点跳转
       * @param {String} id 要跳转的锚点 id
       * @param {Number} offset 跳转位置的偏移量
       * @returns {Promise}
       */
      navigateTo (id, offset) {
        return new Promise((resolve, reject) => {
          if (!this.useAnchor) {
            reject(Error('Anchor is disabled'))
            return
          }
          offset = offset || parseInt(this.useAnchor) || 0
          // #ifdef APP-PLUS-NVUE
          if (!id) {
            dom.scrollToElement(this.$refs.web, {
              offset
            })
            resolve()
          } else {
            this._navigateTo = {
              resolve,
              reject,
              offset
            }
            this.$refs.web.evalJs('uni.postMessage({data:{action:"getOffset",offset:(document.getElementById(' + id + ')||{}).offsetTop}})')
          }
          // #endif
          // #ifndef APP-PLUS-NVUE
          let deep = ' '
          // #ifdef MP-WEIXIN || MP-QQ || MP-TOUTIAO
          deep = '>>>'
          // #endif
          const selector = uni.createSelectorQuery()
            // #ifndef MP-ALIPAY
            .in(this._in ? this._in.page : this)
            // #endif
            .select((this._in ? this._in.selector : '._root') + (id ? `${deep}#${id}` : '')).boundingClientRect()
          if (this._in) {
            selector.select(this._in.selector).scrollOffset()
              .select(this._in.selector).boundingClientRect()
          } else {
            // 获取 scroll-view 的位置和滚动距离
            selector.selectViewport().scrollOffset() // 获取窗口的滚动距离
          }
          selector.exec(res => {
            if (!res[0]) {
              reject(Error('Label not found'))
              return
            }
            const scrollTop = res[1].scrollTop + res[0].top - (res[2] ? res[2].top : 0) + offset
            if (this._in) {
              // scroll-view 跳转
              this._in.page[this._in.scrollTop] = scrollTop
            } else {
              // 页面跳转
              uni.pageScrollTo({
                scrollTop,
                duration: 300
              })
            }
            resolve()
          })
          // #endif
        })
      },

      /**
       * @description 获取文本内容
       * @return {String}
       */
      getText (nodes) {
        let text = '';
        (function traversal (nodes) {
          for (let i = 0; i < nodes.length; i++) {
            const node = nodes[i]
            if (node.type === 'text') {
              text += node.text.replace(/&amp;/g, '&')
            } else if (node.name === 'br') {
              text += '\n'
            } else {
              // 块级标签前后加换行
              const isBlock = node.name === 'p' || node.name === 'div' || node.name === 'tr' || node.name === 'li' || (node.name[0] === 'h' && node.name[1] > '0' && node.name[1] < '7')
              if (isBlock && text && text[text.length - 1] !== '\n') {
                text += '\n'
              }
              // 递归获取子节点的文本
              if (node.children) {
                traversal(node.children)
              }
              if (isBlock && text[text.length - 1] !== '\n') {
                text += '\n'
              } else if (node.name === 'td' || node.name === 'th') {
                text += '\t'
              }
            }
          }
        })(nodes || this.nodes)
        return text
      },

      /**
       * @description 获取内容大小和位置
       * @return {Promise}
       */
      getRect () {
        return new Promise((resolve, reject) => {
          uni.createSelectorQuery()
            // #ifndef MP-ALIPAY
            .in(this)
            // #endif
            .select('#_root').boundingClientRect().exec(res => res[0] ? resolve(res[0]) : reject(Error('Root label not found')))
        })
      },

      /**
       * @description 暂停播放媒体
       */
      pauseMedia () {
        for (let i = (this._videos || []).length; i--;) {
          this._videos[i].pause()
        }
        // #ifdef APP-PLUS
        const command = 'for(var e=document.getElementsByTagName("video"),i=e.length;i--;)e[i].pause()'
        // #ifndef APP-PLUS-NVUE
        let page = this.$parent
        while (!page.$scope) page = page.$parent
        page.$scope.$getAppWebview().evalJS(command)
        // #endif
        // #ifdef APP-PLUS-NVUE
        this.$refs.web.evalJs(command)
        // #endif
        // #endif
      },

      /**
       * @description 设置媒体播放速率
       * @param {Number} rate 播放速率
       */
      setPlaybackRate (rate) {
        this.playbackRate = rate
        for (let i = (this._videos || []).length; i--;) {
          this._videos[i].playbackRate(rate)
        }
        // #ifdef APP-PLUS
        const command = 'for(var e=document.getElementsByTagName("video"),i=e.length;i--;)e[i].playbackRate=' + rate
        // #ifndef APP-PLUS-NVUE
        let page = this.$parent
        while (!page.$scope) page = page.$parent
        page.$scope.$getAppWebview().evalJS(command)
        // #endif
        // #ifdef APP-PLUS-NVUE
        this.$refs.web.evalJs(command)
        // #endif
        // #endif
      },

      /**
       * @description 设置内容
       * @param {String} content html 内容
       * @param {Boolean} append 是否在尾部追加
       */
      setContent (content, append) {
        if (!append || !this.imgList) {
          this.imgList = []
        }
        const nodes = new Parser(this).parse(content)
        // #ifdef APP-PLUS-NVUE
        if (this._ready) {
          this._set(nodes, append)
        }
        // #endif
        this.$set(this, 'nodes', append ? (this.nodes || []).concat(nodes) : nodes)

        // #ifndef APP-PLUS-NVUE
        this._videos = []
        this.$nextTick(() => {
          this._hook('onLoad')
          this.$emit('load')
        })

        if (this.lazyLoad || this.imgList._unloadimgs < this.imgList.length / 2) {
          // 设置懒加载，每 350ms 获取高度，不变则认为加载完毕
          let height = 0
          const callback = rect => {
            if (!rect || !rect.height) rect = {}
            // 350ms 总高度无变化就触发 ready 事件
            if (rect.height === height) {
              this.$emit('ready', rect)
            } else {
              height = rect.height
              setTimeout(() => {
                this.getRect().then(callback).catch(callback)
              }, 350)
            }
          }
          this.getRect().then(callback).catch(callback)
        } else {
          // 未设置懒加载，等待所有图片加载完毕
          if (!this.imgList._unloadimgs) {
            this.getRect().then(rect => {
              this.$emit('ready', rect)
            }).catch(() => {
              this.$emit('ready', {})
            })
          }
        }
        // #endif
      },

      /**
       * @description 调用插件钩子函数
       */
      _hook (name) {
        for (let i = plugins.length; i--;) {
          if (this.plugins[i][name]) {
            this.plugins[i][name]()
          }
        }
      },

      // #ifdef APP-PLUS-NVUE
      /**
       * @description 设置内容
       */
      _set (nodes, append) {
        this.$refs.web.evalJs('setContent(' + JSON.stringify(nodes).replace(/%22/g, '') + ',' + JSON.stringify([this.containerStyle.replace(/(?:margin|padding)[^;]+/g, ''), this.errorImg, this.loadingImg, this.pauseVideo, this.scrollTable, this.selectable]) + ',' + append + ')')
      },

      /**
       * @description 接收到 web-view 消息
       */
      _onMessage (e) {
        const message = e.detail.data[0]
        switch (message.action) {
          // web-view 初始化完毕
          case 'onJSBridgeReady':
            this._ready = true
            if (this.nodes) {
              this._set(this.nodes)
            }
            break
          // 内容 dom 加载完毕
          case 'onLoad':
            this.height = message.height
            this._hook('onLoad')
            this.$emit('load')
            break
          // 所有图片加载完毕
          case 'onReady':
            this.getRect().then(res => {
              this.$emit('ready', res)
            }).catch(() => {
              this.$emit('ready', {})
            })
            break
          // 总高度发生变化
          case 'onHeightChange':
            this.height = message.height
            break
          // 图片点击
          case 'onImgTap':
            this.$emit('imgtap', message.attrs)
            if (this.previewImg) {
              uni.previewImage({
                current: parseInt(message.attrs.i),
                urls: this.imgList
              })
            }
            break
          // 链接点击
          case 'onLinkTap': {
            const href = message.attrs.href
            this.$emit('linktap', message.attrs)
            if (href) {
              // 锚点跳转
              if (href[0] === '#') {
                if (this.useAnchor) {
                  dom.scrollToElement(this.$refs.web, {
                    offset: message.offset
                  })
                }
              } else if (href.includes('://')) {
                // 打开外链
                if (this.copyLink) {
                  plus.runtime.openWeb(href)
                }
              } else {
                uni.navigateTo({
                  url: href,
                  fail () {
                    uni.switchTab({
                      url: href
                    })
                  }
                })
              }
            }
            break
          }
          case 'onPlay':
            this.$emit('play')
            break
          // 获取到锚点的偏移量
          case 'getOffset':
            if (typeof message.offset === 'number') {
              dom.scrollToElement(this.$refs.web, {
                offset: message.offset + this._navigateTo.offset
              })
              this._navigateTo.resolve()
            } else {
              this._navigateTo.reject(Error('Label not found'))
            }
            break
          // 点击
          case 'onClick':
            this.$emit('tap')
            this.$emit('click')
            break
          // 出错
          case 'onError':
            this.$emit('error', {
              source: message.source,
              attrs: message.attrs
            })
        }
      }
      // #endif
    }
  }
</script>

<style>
  /* #ifndef APP-PLUS-NVUE */
  /* 根节点样式 */
  ._root {
    padding: 1px 0;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
  }

  /* 长按复制 */
  ._select {
    user-select: text;
  }
  /* #endif */
</style>
